1. Field of the Invention
The present invention relates to an electric contact that is connected to an electrical part such as a semiconductor device (hereinafter, called an “IC package”), and related to a socket for electrical parts onto which the electric contact is located.
2. Description of the Prior Art
Conventionally, the IC socket, which accommodates the IC package as an “electrical part” removably, is known as the above-mentioned “socket for an electrical part”.
The conventional IC package comprises a package body which has a rectangular shape, for example, and has terminals.
On the other hand, the conventional IC socket comprises socket body to be located on the wiring substrate. The socket body is provided with a contact pin unit comprising a plurality of contact pins for electrically connecting the terminals of the IC package and the wiring substrate.
In addition, the socket body comprises a floating plate located so as to be vertically movable under the state of being urged upward by springs, and the IC package is accommodated on the floating plate.
When the IC socket is located on the wiring substrate and is used, the floating plate accommodates the IC package on itself and moves downward by being pressed from above.
Then, the upper side contact portions of the contact pins are pressed to the terminals of the IC package via the through holes formed in the floating plate, while the lower contact portions of the contact pins are pressed to the electrodes of the wiring substrate.
Under such situation, the electrical currents flow between the wiring substrate and the IC package through the contact pins, and a burn-in test etc. is performed.
As such contact pins, an electrical contact, in which a cylindrical first plunger (i.e. barrel) and a rod-shaped second plunger (i.e. plunger) is interlinked in an extensible manner via an urging member (i.e. spring), has been proposed (see Japanese laid-open patent publication 2010-91436).